Well that depends on how you got your game and what game is it, as not all games have multiple revisions (mostly two I think)This is really helpful, thanks. How do you know which version of the game you have, though? I tried using your step-by-step for applying cheats MANY pages back, but couldn't get it to work no matter how much I tried, even following your instructions to the letter. I have no idea what I'm doing wrong.
I will take Smash Bros. Melee as an example.
If you downloaded it because your disc is not functional anymore (of course that happens), then the website should have the v1.0, v1.1 or v1.2 legend at the side of the name, and you can also check the MD5 in redump.org to confirm the version.
Here are the MD5 hashes for all the versions of Smash Melee:
http://smashboards.com/threads/finding-out-your-melee-revision-for-sure.329103/
If you ripped it and still have the original Mini-DVD (game disc) for Melee, you can check the version by checking the inner disc circle, which should have something like:
DOL-GALE 0-00/01/02.
Whatever the last digit is, that's your version:
http://smashboards.com/threads/version-differences-in-melee-1-0-1-1-1-2-pal.321230/
If you still need help, let me know.
What game are you trying to apply cheats to?